This invention relates to an inclinometer adapted to be mounted on a vehicle.
In recent years, inclinometers are mounted on motor cars and other vehicles for quantitatively displaying the inclination of the road surface on which the vehicles are running. Among such inclinometers is included a gear transmission weight type consisting of a drive member including a weight which rotates in response to inclination of a vehicle, a driven member transmitted with the rotational torque of the drive member, and an indicator secured to the shaft of the driven member for displaying the inclination angle. With this type of inclinometer, under a state in which a zero point should be displayed, the zero point can not always be displayed due to the error of the zero point display caused by manufacturing error, error in the horizontal criterion at the time of mounting the inclinometer on the vehicle, and inclination of the vehicle body due to uneven loading.
Accordingly, according to a prior art zero point mechanism of an inclinometer, as shown in FIGS. 1A and 1B, a disc shaped inclination indicator 2 is secured to one end of a driven shaft 1 driven by a drive mechanism, not shown, and a scale board 3 is coaxially disposed adjacent the inclination indicator 2. The scale board 3 is rotatably supported by a guide ring 4. When adjusting the zero point, the scale board 3 is rotated to make its zero point 0 (thick solid graduation) coincide with the display line P of the inclination indicator 2. Thus, if the inclination indicator 2 is so manufactured as to be slightly (.alpha. in FIG. 1A) inclined under the horizontal criterion condition, the scale board 3 is rotated in a direction of arrow a to establish a zero point display as shown in FIG. 1C. The guide ring 4 is marked with digits 0, 20, 40 . . . indicating inclination angles corresponding to respective scale lines of the scale board 3.
According to another prior art inclinometer, a pointer 5 is provided to oppose the periphery of an indicator 2a secured to one end of a driven shaft, as shown in FIG. 2A, and the pointer is rotated in the direction of arrows to set it at the zero point of the indicator 2a. Particularly, if the indicator 2a is inclined by .beta. (FIG. 2A) under the horizontal criterion condition, the pointer 5 is rotated in a direction of arrow b to establish a zero point display as shown in FIG. 2B.
In these zero point mechanisms, however, when the zero point adjustment is completed, in most cases, the display line of the indicator and the zero point 0 of the scale board 3 of the pointer 5 do not posture horizontally, thus not only impairing appearance, but also making it difficult to read the inclinometer.